Simulation works on laptop. I have a simple R Diode circuit to simulate. I want to change some of the characteristics of the diode, Isat and V diode turn-on. I'm using a 1N914, where do I change characteristics? Tried the propety editor, but don't see any place there to make change.

SPICE was originally programmed on a mainframe computer. PSPICE is basically similar algorythms that were ported over to run on a personal computer. There are many, many different PSPICE circuit emulators. The SPICE directives they use are all very similar if not identical, but the underlying software is coded differently.

Have a look at this page http://www.allaboutcircuits.com/vol_3/chpt_3/14.html. The model parameters do not exactly correspond to datasheet parameters. You could try changing a few parameters, like IS, N or RS so that you have a IF against VF curve according to your requirement, hovewer you have to realise that other characteristics of the diode would also be different.

Furthermore, each parameters in the model might seem relate to or describe a physical semiconductor property, but in practice most models are developed with curve fitting methods instead, so changing one parameter might not result like what you expect.

VJ is the junction potential. As I wrote in my earlier post, there's rarely one to one correlation between a SPICE parameter and actual physical characteristic. Changing VJ will change the cut-off voltage, but also a lot of other characteristics.

The best method to achieve what you required, as outlined in the referenced page, is to change the SPICE parameters and re-simulate and compare the transfer curve against the one that you want. Not a fun processes, you might need to perform a lot of iterations to achieve suitable transfer curve. Note that this method has to be done separately for AC parameters if you also simulate AC response.